超声辅助均相离子液体微萃取-高效液相色谱法测定丹参中的丹参酮

建立超声辅助均相离子液体微萃取-高效液相色谱法(UA-HILME-HPLC)同时测定丹参中的二氢丹参酮、丹参酮Ⅰ、隐丹参酮和丹参酮ⅡA。本研究以水溶性离子液体为萃取剂,以水为传递介质,采用超声波辅助提取目标物,通过向提取液中加入离子对试剂形成水不溶性离子液体,离心后发生相分离,取离子液体部分进行高效液相色谱分析。实验结果表明,超声辅助均相离子液体微萃取法的最佳提取条件为:以140μL[C8MIM][BF4]为萃取剂,以1 m L 0.6 mol/L NH4PF6溶液为离子对试剂,样品溶液p H 5.0,初始提取温度50℃,超声提取时间5 min,超声功率200 W。各目标化合物在线性范围内呈现良好的线性关系(r0.9996),检出限和定量限分别为0.02~0.04μg/m L和0.07~0.13μg/m L,日内和日间精密度(RSD)分别低于3.23%和4.57%,样品加标回收率在83.50~96.23%之间。本法集提取、浓缩、分离和纯化为一体,不使用挥发性有机溶剂,具有提取时间短,样品用量少等优点,可广泛应用于药用植物中活性成分的提取分析。     

离子液体涡旋辅助/表面活性剂乳化-液相微萃取测定牛奶中的三嗪类和苯基脲类除草剂

建立了基于离子液体涡旋辅助/表面活性剂乳化-液相微萃取高效液相色谱测定牛奶中的三嗪类和苯基脲类除草剂残留分析方法。将1-己基-3-甲基咪唑六氟磷酸盐离子液体作为提取剂,离子液体在涡旋辅助作用下分散于牛奶溶液中,同时应用表面活性剂作为乳化剂,加速分析物从水相到离子液体的传质速率,防止离心时离子液体附着于管壁。使用醋酸和硫酸钠去除牛奶中的脂肪和蛋白质,减少对分析物的提取干扰。同时考查了离子液体的种类和体积,表面活性剂的种类和体积,涡旋提取时间,离子对浓度和样品p H值对萃取效率的影响。在优化实验条件下,1~400μg/L范围内线性良好,相关系数为0.9963~0.9998;最小检出限和定量限以最小提取浓度的3倍和10倍信噪比计算分别为0.018~0.095μg/L和0.10~0.38μg/L。使用该方法进行了低脂牛奶、高压消毒牛奶、纯牛奶和鲜牛奶中6种分析物的检测,同时进行3个不同浓度的添加回收实验,回收率为70.34~100.02%,RSD为2.06~9.95%。     

涡旋辅助离子液体双水相萃取五味子中木脂素类化合物

建立一种简单、高效、绿色的涡旋辅助离子液体双水相法萃取五味子中7种木脂素类化合物,结合高效液相色谱法对目标物进行分离和定量。研究以离子液体[C₄mim]BF₄为萃取剂,以MgSO₄为成相盐,在涡旋辅助作用下形成双水相体系且目标物则被萃取至离子液体相中,分别对双水相体系的组成和萃取条件进行了考察和优化,并进行了方法评价。实验结果表明,当[C₄mim]BF₄体积为500 μL,MgSO₄的用量为1.6 g,涡旋1.5 min,以3000 r/min离心10 min时,五味子中木脂素类化合物的提取量达到最大值。各目标分析物在线性范围内具有良好的线性关系（r>0.9995）,日间和日内精密度分别低于3.97%和4.19%,检出限（LOD）和定量限（LOQ）分别为0.20~6.98和0.65~23.26 ng·mL?1,加标回收率在72.22%~97.19%之间。与传统提取方法相比,本法缩短了提取时间,减少了萃取剂用量,具有操作简单、省时、高效等优点,可用于木脂素类化合物的提取与检测。     

微波辅助衍生-离子液体分散液液微萃取-高效液相色谱法检测牛奶中氨基糖苷类抗生素残留

将微波辅助衍生法与离子液体分散液液微萃取法相结合,建立了牛奶中链霉素、庆大霉素、卡那霉素、妥布霉、小诺霉素、阿米卡星和新霉素等7种氨基糖苷类抗生素(AGs)的快速萃取、衍生方法。本研究以氯甲酸芴甲酯(FMOC-Cl)为衍生试剂,1-辛基-3-甲基咪唑六氟磷酸盐(Omim]PF6)为提取剂,甲醇为分散剂,将微波辅助衍生和离子液体分散液液微萃取相结合,使目标化合物被衍生的同时被萃取和富集到离子液体中,并通过高效液相色谱荧光检测器进行定量检测。实验结果表明,各化合物在线性范围内具有较好的线性关系(r0.9989),检出限为0.11~0.57μg/L。加标样品回收率在91.95~106.33%之间,其RSD为1.39~5.92%。本法操作简单,灵敏度高,结果可靠,可广泛应用于牛奶样品中氨基糖苷类抗生素的检测。     

超声辅助离子液体分散液相微萃取石墨炉原子吸收光谱法测定食品中铅镉

建立了一种简单高效的超声辅助离子液体分散液液微萃取(UA-IL-DLLME)结合石墨炉原子吸收光谱法(GFAAS)测定食品中超痕量铅镉。以二乙基二硫代磷酸铵(DDTP)为配位剂,离子液体1-丁基-3-甲基咪唑六氟磷酸盐[C_4Mim][PF_6]为萃取剂,超声用于辅助分散离子液体和加速传质。考察优化了影响萃取效率的主要参数如离子液体的种类和体积、样品液p H、螯合剂的用量、超声时间、离心转速与时间等。在最优的萃取条件下,镉铅的校准曲线分别在0.05~20μg/L和0.5~40μg/L范围呈良好的线性,相关系数分别为0.9983 and 0.9969,检出限(S/N=3)分别为0.032和0.32μg/kg,相对标准偏差(RSD,n=11)分别为1.3%和1.8%。大米和白兰地中镉铅3个水平1.60、16.00、32.00μg/kg的平均加标回收率在95.2~102%范围。方法已成功用于检测不同食品中镉铅含量。     

高效液相色谱法同时测定虎杖中五种活性成分

本文建立了虎杖中五种活性成分:虎杖苷、白藜芦醇、大黄素-8-O-β-D-葡萄糖苷、大黄素、大黄素甲醚的高效液相色谱分析方法。色谱柱为Agilent Zorbax SB C18柱(4.6×250 mm,5μm),流动相为乙腈(A)和水(B),梯度洗脱程序为:0~40 min,15.0~50.0%A;40~60 min,50.0~90.0%A。柱温为40℃,检测波长为290 nm,流速为1.0 mL/min。五种成分线性良好(R0.999),保留时间相对标准偏差(RSD)介于0.14~1.67%,峰面积RSD介于0.96~2.96%,加标回收率介于96.8~104.7%。优化了虎杖的提取条件,最佳条件为60%乙醇超声提取30 min。对10批虎杖样品分析结果表明:虎杖苷和大黄素-8-O-β-D-葡萄苷是虎杖乙醇提取物中两种含量最高的活性成分,含量范围分别为9.80~20.42 mg/g和5.56~24.45 mg/g。白藜芦醇和大黄素的含量范围分别为1.07~5.94 mg/g和3.79~17.85 mg/g,而大黄素甲醚含量为0.57~1.69 mg/g。该高效液相色谱法重复性好、精密度高,可用于虎杖中五种活性成分的同时测定。     

离子液体乳相液液微萃取结合高效液相色谱法测定豆奶中的磺酰脲类除草剂

建立一种绿色、高效的涡旋/超声协同乳化离子液体乳相液液微萃取法,用于提取和富集豆奶中残留的噻吩磺隆、甲磺隆、醚苯磺隆、氯磺隆、苄嘧磺隆和吡嘧磺隆等6种磺酰脲类除草剂,并结合高效液相色谱法对目标分析物进行分离与测定。本方法以离子液体为萃取剂,以改性蒙脱土为固相分散吸附剂,经涡旋和超声协同作用促使离子液体乳化,形成离子液体乳相萃取液,增加离子液体与目标分析物的接触面积,通过改性蒙脱土对结合了目标分析物的离子液体进行吸附,经离心后改性蒙脱土与样液实现相分离,用定量乙腈解析改性蒙脱土中的目标分析物,解析液过滤后进行色谱分析。结果表明,在7.80~500.00 μg/L的线性范围内各目标分析物具有良好的线性关系（r>0.9990）,其检出限（LODs）与定量限（LOQs）分别为1.60~3.15和5.34~10.12 μg/L。各目标分析物的日内精密度和日间精密度（RSD）分别为1.31%~5.07%和1.12%~6.63%,加标回收率在81.55%~116.44%之间,相对标准偏差在0.05%~8.91%之间。本法以离子液体为萃取剂,将涡旋/超声协同乳化与离子液体液液微萃取相结合,集样品提取、分离、净化于一体,具有萃取效率高、操作简单和绿色环保等优点。     

表面活性剂在盾叶薯蓣中萃取皂苷的应用研究

分别以非离子、阳离子、阴离子以及两性表面活性剂水溶液为萃取剂,借助超声波辅助技术,探究从盾叶薯蓣萃取薯蓣皂苷的过程中,表面活性剂的类型、超声波参数对薯蓣皂苷元产率的影响。研究表明：以溶质质量分数为1．5％的辛基酚聚氧乙烯醚（OP．10）水溶液为萃取剂,超声波频率为25．80kHz,超声时间为40min时,提取的薯蓣皂苷元的纯度最高,可达95．3％。     

虎杖中虎杖苷提取工艺的响应面优化方法

考察虎杖中虎杖苷的最佳提取工艺,采用无毒的乙醇作为提取溶剂,利用响应面法优化了虎杖中虎杖苷的提取条件,采用紫外分光光度法和HPLC法检测虎杖苷的含量。最佳提取条件为乙醇浓度78%,提取温度51℃,料液比10.70 mL/g,提取时间为2 h,得到虎杖苷理论吸光度值为0.445,与实际值0.439接近。经HPLC检测得到虎杖苷提取率为1.83%,与最高含量理论值2%接近。实验结果表明,采用响应曲面法优化得到的提取条件参数准确、可靠,具有实用价值。     

高效液相色谱-串联质谱法测定厚朴中的厚朴酚与和异构厚朴酚

建立一种微波辅助离子液体均相液液微萃取高效液相色谱-串联质谱法,测定了中药材厚朴中的厚朴酚与和厚朴酚。本研究以离子液体为萃取溶剂,样品经微波提取后,向所获得的样品提取液中加入离子对试剂六氟磷酸铵(NH4PF6),采用均相液液微萃取法分离富集目标分析物,并通过高效液相色谱-串联质谱进行定性定量检测。本研究对影响萃取效率的各个条件进行单因素和响应面优化。实验结果表明,目标分析物在检测浓度范围内具有较好的线性关系(R0.9999),检出限和定量限分别为17.2～3.9ng/g和57.4～79.6 ng/g,样品加标回收率在89.25%～95.00%之间。与传统超声提取法和回流提取法相比,本法在溶剂用量、萃取时间上具有一定的优势,可用于中草药及相关医药产品中厚朴酚与和厚朴酚的提取分析。     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of     

The Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.